HIGH TEMPERATURE FIBERS OF YAG AND ZRSIO4 FOR COMPOSITES

CERAMIC COMPOSITE MATERIALS FOR MILITARY SYSTEMS OFFER PERFORMANCE, WEIGHT AND COST ADVANTAGES OVER COMPETING MATERIALS. INCREASING DEMANDS ON THE STRENGTH AND TEMPERATURE TOLERANCE FOR THESE MATERIALS WILL REQUIRE INNOVATIVE APPROACHES IN COMPOSITION AND FABRICATION. COMPOSITE MATERIALS COMPOSED OF SINGLE CRYSTAL WHISKERS SHOW PROMISING TENSILE STRENGTH BUT HAVE PROVEN DIFFICULT TO GROW AND HAVE NOT BEEN PRODUCED IN USEFUL LENGTHS. LASERGENICS CORPORATION IS PROPOSING TO INVESTIGATE THE GROWTH OF SINGLE CRYSTAL FIBERS OF YAG AND ZRSIO4 BY THE LASER-HEATED PEDESTAL-GROWTH TECHNIQUE. THE MELTING POINT OF YAG IS 1970'C AND THAT OF ZRSIO4 IS 2820'C MAKING THEM DIFFICULT TO GROW IN ANY CONFIGURATION. WE HAVE ACHIEVED INITIAL SUCCESS IN GROWING BOTH OF THESE MATERIALS BUT IN ORDER TO ACHIEVE COMMERCIALLY INTERESTING LENGTHS OF THESE MATERIALS, THE GROWTH MUST BE OPTIMIZED. FIBERS OF THESE MATERIALS WILL BE GROWN, THEIR CRYSTAL STRUCTURE AND MORPHOLOGY CHARACTERIZED AND STRENGTH MEASUREMENTS MADE DURING THE PHASE I EFFORT. GROWTH OF SINGLE CRYSTAL FIBERS OF MULTI-METER LENGTHS OF THESE VERY HIGH MELTING POINT MATERIALS, INCORPORATION INTO CERAMIC MATRIX COMPOSITES AND THE TESTING OF THESE COMPOSITES WILL BE THE BASIS OF THE PHASE II EFFORT.